Again and again people seem to refer to soft pastels as chalks, chalk crayons, chalk pastels and so forth. Even large art institutions seem still to be doing this. It creates the impression that chalks and pastels are the same thing and in my opinion it keeps the myth alive that pastel paintings are somehow worth less than paintings created with other art materials.
Now you might think me over-sensitive to semantics. But there are still many people who rate pastel (and watercolour and coloured pencil etc) as somehow 'less' than oil paints. Some major art competitions only allow oils and acrylics in. Pastel paintings are sold for lower prices than oil paintings. I think we should try and find out some facts and bust some myths.
Chalks are used for blackboards and pavement fun. They contain chalk (calcium carbonate, but I was never any good at science so don't drill me on the elements), plaster of Paris and dyes for colouring. Look for example at the helpful FAQ of Crayola for more info on their chalks. It seems like it makes sense to call these crayons 'chalks'.
Soft pastel looks and feels a bit like chalk. So it is understandable to call them 'chalks' as well. But artists' pastels do not contain any chalk. At all. None. Whatsoever. Nor are they made for black boards or pavements. So although I understand that the word 'chalk' has crept into common language to refer to pastels, I cannot extend the same understanding to world famous museums, curators or artists using the word as well.
I have not checked all pastel brands for their use of chalk (I know some do use it such as Mount Vision pastels) . Nor have I researched whether it is bad to put chalk into pastel. I am not here to bad-mouth chalk. But what I do know is that often artists' quality soft pastels do not contain chalk. So why on earth call them chalks and risk demoting them to the region of kindergarten work?
Seriously, there is no chalk in any of these pastels!
Is Chalk Bad?
I don't know. I don't think so. I don't think chalk is a particularly bad ingredient for art materials. So just because your pastels contain chalk does not make them bad quality. I suspect, however, that there is no reason for soft pastels to contain chalk, as it does not function as a binder and it is not a pigment required for any of the colours. We would much rather paint with pigment than a superfluous material like chalk. So I suspect, but don't quote me on this, that some cheaper brands use it as a filler to save on pigment costs.
Why Can't I Call Pastels Chalks?
Because soft pastels are not the same as chalks (the kids' material) and it feeds the impression that they are. It causes confusion. If people keep thinking that pastels and chalks are the same, pastel will never be considered a proper, archival and professional art material. Why call a fish soup, fish soup, if it does not contain any fish? So let's call it by its proper name: soft pastel.
What is a Binder?
A binder is a material to keep the powdery pigment together so that it loses its powdery form. It is hard to draw or paint with coloured powder, so they mix it up with something to create a material that is usable. The binder for oil paints is usually linseed oil which makes for a very usable goo (technical term! 😉 ) that has been used for centuries. For pastel they add a binder to create a paste, which can be rolled into pastel sticks. This way we can actually hold and use a pastel. Of course the binder has to be something that does not alter the pigment or the archival qualities of the painting.
Despite Talens describing all their pastels as " a soft type of chalk" (Arch!) on their website, they tell me that their Rembrandt pastels contain NO chalk at all. Their carré pastels (square hard pastels that come in earth colours) do contain chalk. Their Rembrandt soft pastels are just pigment+binder and they use tragacanth gum or kaoline clay* as a binder, but they use as little as possible. Some pigments will hold together easier than others and so the amount of binder varies per pigment. Talens won't reveal the exact recipe of their pastels.
Unison tells me that their specific recipe for their pastels is secret, just like Talens. But they also tell me that they 'mostly use no binders' and might use a 'very simple starch solution' if required. There is no chalk or gum arabic in any of their pastels and they only use a little kaoline* or China clay for structure. They strongly believe in keeping things simple and honest.
* I can’t vouch for this website but it has a seemingly useful description of the differences between Kaoline Clay and Calcium Carbonate HERE.
Soft Pastel is Soft Pastel
Soft pastels are not chalks. They usually don't contain chalk and are nothing like blackboard or pavement chalks, save for the shape and feel. Just like any other artists quality art material, soft pastels are made up of pigment and a binder to keep it in a certain shape. The quality of the pigments, binders and the process of making the art materials should define whether they are professional materials or not. Let's just all agree to call pastel by it's proper name and not by something that it is not.
How Unisons are Made
What makes Unison pastels so amazing in texture is the fact they make their pastels by hand. Other professional pastel makers do this as well and it shows in the quality of the pastel (Schmincke, Terry Ludwig).
This beautiful video shows very well how Unison makes their pastels by hand. It really makes me want to start painting (thank you Unison, for allowing me to share this):
This video has no sound
I found this hilarious anecdote from the late Maggie Price(President of the International Association of Pastel Societies)
I'll never forget the incident some years ago when I went to interview Ramon Kelley for The Pastel Journal. He was very serious, very focused, and I was a little intimidated. Then, at some point, the definition of pastel came up. With a perfectly straight face and his serious demeanor, he said, "There's a spot out behind my studio where the students who called it chalk are buried." I burst out laughing and from then on the interview was less formal."